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Innovative 4-Stroke Performance Products

BBR  |  SKU: 411-HXR-5400

BBR 88cc Flat Top Piston Big Bore Kit

$26995 USD $36995

Item Fitment

BBR 88cc Flat Top Piston Big Bore Kit - confirmed fit on the following bikes.

  • 2004 - Present Honda CRF50
  • 2000 - Present Honda XR50

Shipping & Taxes

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US Customers - Taxes (if applicable) will be charged at checkout.

International Customers - Duties/Taxes will be paid at the time of delivery (not checkout).

Description

Convert your CRF/XR50 to an 88cc screamer with this complete kit. Everything is included to upgrade the performance of you mini-bike. This kit uses your stock CRF/XR50 cylinder head.

Also fits 1988-1999 Z50R with short piston.


  • Aluminum BBR cylinder
  • Special 52mm piston specially designed to work with your stock cylinder head's combustion chamber
  • BBR special grind camshaft take full advantage of the large piston for great performance
  • Special BBR tapered aluminum intake manifold adapts the large carb to the stock intake port size
  • 18mm carb includes extra main and pilot jets for easy tuning
  • Also includes CR style throttle, cable, air filter and top end gasket kit

Installation Note 1: Throttle unit included with kit will only work with 7/8" handlebars and will not mount to stock XR/CRF50 handlebars. Stock handlebars are 3/4".

Installation Note 2: This kit will not work with the Honda XR/CRF70 or other big port cylinder heads. It is designed for the tiny combustion chamber of the OEM Honda XR/CRF50 cylinder head. The flat top piston dome will result in an extremely low compression ratio when combine with the XR/CRF70 type cylinder head. The result is a motor that makes less horsepower than stock. Click this link for the BBR bore kit for the CRF/XR70.


BBR General Jetting Guidelines Chart


BBR 88cc Flat Top Piston Bore Kit Instructions

Customer Reviews

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H
Hunter Call

Everything is high quality except the carburetor, I’ve had nothing but issues with it, the threads stripped out with barely any force it’s a pain in the hinder to change jets in and it’s a pile of Chinese junk. I recommend to buy just the 88cc kit without the carburetor and intake ect.. and outsource the other parts

BBR Motorsports

BBR 88cc Flat Top Piston Bore Kit - 411-HXR-5400
BBR

BBR 88cc Flat Top Piston Big Bore Kit

$26995 USD $36995

Convert your CRF/XR50 to an 88cc screamer with this complete kit. Everything is included to upgrade the performance of you mini-bike. This kit uses your stock CRF/XR50 cylinder head.

Also fits 1988-1999 Z50R with short piston.


  • Aluminum BBR cylinder
  • Special 52mm piston specially designed to work with your stock cylinder head's combustion chamber
  • BBR special grind camshaft take full advantage of the large piston for great performance
  • Special BBR tapered aluminum intake manifold adapts the large carb to the stock intake port size
  • 18mm carb includes extra main and pilot jets for easy tuning
  • Also includes CR style throttle, cable, air filter and top end gasket kit

Installation Note 1: Throttle unit included with kit will only work with 7/8" handlebars and will not mount to stock XR/CRF50 handlebars. Stock handlebars are 3/4".

Installation Note 2: This kit will not work with the Honda XR/CRF70 or other big port cylinder heads. It is designed for the tiny combustion chamber of the OEM Honda XR/CRF50 cylinder head. The flat top piston dome will result in an extremely low compression ratio when combine with the XR/CRF70 type cylinder head. The result is a motor that makes less horsepower than stock. Click this link for the BBR bore kit for the CRF/XR70.


BBR General Jetting Guidelines Chart


BBR 88cc Flat Top Piston Bore Kit Instructions
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